One of the things about Standard Gauge is one can never be absolutely sure if what you just got is "original" or not (unless, of course, you're lucky enough to purchase something from the original owner or relative.) Since these pieces are so old, and repair/restore is a normal thing to do, you just never know. 
I recently picked up a second 512; like the first one, it has the cotter pin truck attachments, oil label and (2) brake wheel support stanchions. It has a type "T.3" latch coupler on one end (according to the Greenberg book (page 389) all 512s were so equipped), but...the other end has a type "T.3s" coupler, so it has the additional "slot coupler" feature.
Here's one end:
...and here's the other:
(I should mention the glare from the light in this photo makes this look much newer/cleaner than it really is...)
No mention of a transition type car is to be found in the Greenberg book; this car certainly looks to be original, as it has a similar patina and level of wear throughout.
Anyone care to take a guess?
Mark in Oregon
